xfs: introduce a file mapping exchange log intent item

Introduce a new intent log item to handle exchanging mappings between
the forks of two files.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

2 files changed, 41 insertions, 3 deletions

diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
index 16872972e1e9..09024431cae9 100644
--- a/fs/xfs/libxfs/xfs_log_format.h
+++ b/fs/xfs/libxfs/xfs_log_format.h
@@ -117,8 +117,9 @@ struct xfs_unmount_log_format {
 #define XLOG_REG_TYPE_ATTRD_FORMAT	28
 #define XLOG_REG_TYPE_ATTR_NAME	29
 #define XLOG_REG_TYPE_ATTR_VALUE	30
-#define XLOG_REG_TYPE_MAX		30
-
+#define XLOG_REG_TYPE_XMI_FORMAT	31
+#define XLOG_REG_TYPE_XMD_FORMAT	32
+#define XLOG_REG_TYPE_MAX		32
 
 /*
  * Flags to log operation header
@@ -243,6 +244,8 @@ typedef struct xfs_trans_header {
 #define	XFS_LI_BUD		0x1245
 #define	XFS_LI_ATTRI		0x1246  /* attr set/remove intent*/
 #define	XFS_LI_ATTRD		0x1247  /* attr set/remove done */
+#define	XFS_LI_XMI		0x1248  /* mapping exchange intent */
+#define	XFS_LI_XMD		0x1249  /* mapping exchange done */
 
 #define XFS_LI_TYPE_DESC \
 	{ XFS_LI_EFI,		"XFS_LI_EFI" }, \
@@ -260,7 +263,9 @@ typedef struct xfs_trans_header {
 	{ XFS_LI_BUI,		"XFS_LI_BUI" }, \
 	{ XFS_LI_BUD,		"XFS_LI_BUD" }, \
 	{ XFS_LI_ATTRI,		"XFS_LI_ATTRI" }, \
-	{ XFS_LI_ATTRD,		"XFS_LI_ATTRD" }
+	{ XFS_LI_ATTRD,		"XFS_LI_ATTRD" }, \
+	{ XFS_LI_XMI,		"XFS_LI_XMI" }, \
+	{ XFS_LI_XMD,		"XFS_LI_XMD" }
 
 /*
  * Inode Log Item Format definitions.
@@ -879,6 +884,37 @@ struct xfs_bud_log_format {
 };
 
 /*
+ * XMI/XMD (file mapping exchange) log format definitions
+ */
+
+/* This is the structure used to lay out an mapping exchange log item. */
+struct xfs_xmi_log_format {
+	uint16_t		xmi_type;	/* xmi log item type */
+	uint16_t		xmi_size;	/* size of this item */
+	uint32_t		__pad;		/* must be zero */
+	uint64_t		xmi_id;		/* xmi identifier */
+
+	uint64_t		xmi_inode1;	/* inumber of first file */
+	uint64_t		xmi_inode2;	/* inumber of second file */
+	uint64_t		xmi_startoff1;	/* block offset into file1 */
+	uint64_t		xmi_startoff2;	/* block offset into file2 */
+	uint64_t		xmi_blockcount;	/* number of blocks */
+	uint64_t		xmi_flags;	/* XFS_EXCHMAPS_* */
+	uint64_t		xmi_isize1;	/* intended file1 size */
+	uint64_t		xmi_isize2;	/* intended file2 size */
+};
+
+#define XFS_EXCHMAPS_LOGGED_FLAGS		(0)
+
+/* This is the structure used to lay out an mapping exchange done log item. */
+struct xfs_xmd_log_format {
+	uint16_t		xmd_type;	/* xmd log item type */
+	uint16_t		xmd_size;	/* size of this item */
+	uint32_t		__pad;
+	uint64_t		xmd_xmi_id;	/* id of corresponding xmi */
+};
+
+/*
  * Dquot Log format definitions.
  *
  * The first two fields must be the type and size fitting into
diff --git a/fs/xfs/libxfs/xfs_log_recover.h b/fs/xfs/libxfs/xfs_log_recover.h
index 9fe7a9564bca..47b758b49cb3 100644
--- a/fs/xfs/libxfs/xfs_log_recover.h
+++ b/fs/xfs/libxfs/xfs_log_recover.h
@@ -75,6 +75,8 @@ extern const struct xlog_recover_item_ops xlog_cui_item_ops;
 extern const struct xlog_recover_item_ops xlog_cud_item_ops;
 extern const struct xlog_recover_item_ops xlog_attri_item_ops;
 extern const struct xlog_recover_item_ops xlog_attrd_item_ops;
+extern const struct xlog_recover_item_ops xlog_xmi_item_ops;
+extern const struct xlog_recover_item_ops xlog_xmd_item_ops;
 
 /*
  * Macros, structures, prototypes for internal log manager use.